Medical robotic systems such as teleoperative systems used in performing minimally invasive surgical procedures offer many benefits over traditional open surgery techniques, including less pain, shorter hospital stays, quicker return to normal activities, minimal scarring, reduced recovery time, and less injury to tissue. Consequently, demand for such medical robotic systems is strong and growing.
One example of such a medical robotic system is the da Vinci® Surgical System from Intuitive Surgical, Inc., of Sunnyvale, Calif., which is a minimally invasive robotic surgical system. The da Vinci® Surgical System has a number of robotic arms that move attached medical devices, such as an image capturing device and Intuitive Surgical's proprietary EndoWrist® articulating surgical instruments, in response to movement of input devices by a surgeon viewing images captured by the image capturing device of a surgical site. Each of the medical devices is inserted through its own minimally invasive incision into the patient and positioned to perform a medical procedure at the surgical site. The incisions are placed about the patient's body so that the surgical instruments may be used to cooperatively perform the medical procedure and the image capturing device may view it without their robotic arms colliding during the procedure.
To perform certain medical procedures, it may be advantageous to use a single entry aperture, such as a minimally invasive incision or a natural body orifice, to enter a patient to perform a medical procedure. For example, an entry guide may first be inserted, positioned, and held in place in the entry aperture. Instruments such as an articulatable camera and a plurality of articulatable surgical tools, which are used to perform the medical procedure, may then be inserted into a proximal end of the entry guide so as to extend out of its distal end. Thus, the entry guide provides a single entry aperture for multiple instruments while keeping the instruments bundled together as it guides them toward the work site.
A number of challenges arise in medical robotic systems using such a bundled unit, however, because of the close proximity of the camera and tool instruments. For example, because the camera instrument has proximal articulations (e.g., joints) that are not visible from the endoscopic camera view, the surgeon can inadvertently drive them to crash into one of the surgical tools while telerobotically moving the camera tip to a different viewing position or orientation. If such a collision occurs, it may cause unwanted motion of the surgical tool(s) that the camera is colliding with and thus potentially harm the patient or otherwise adversely impact the performance of the medical procedure.
Also, since only a limited number of hand-manipulatable input devices are generally available in a medical robotic system, it may be necessary for the operator to temporarily switch association of one of the input devices from its currently associated surgical tool to the camera in order for the operator to telerobotically control positioning of the camera using the input device. Such temporary switching of associations, however, may disrupt the intuitive mapping between the motions of the input device and its associated surgical tool. In particular, it may be necessary to realign the orientation of the input device with that of its associated surgical tool before resuming operation after such temporary switching in order to maintain a sense of telepresence for the surgeon.